Quantifying the effects of short-term heat stress at booting stage on nonstructural carbohydrates remobilization in rice

Publication date: Available online 23 October 2019Source: The Crop JournalAuthor(s): Fengxian Zhen, Junjie Zhou, Aqib Mahmood, Wei Wang, Xini Chang, Bing Liu, Leilei Liu, Weixing Cao, Yan Zhu, Liang TangAbstractExtreme heat stress events are becoming more frequent under anticipated climate change, which can have devastating impacts on rice growth and yield. To quantify the effects of short-term heat stress at booting stage on nonstructural carbohydrates (NSC) remobilization in rice, two varieties (Nanjing 41 and Wuyunjing 24) were subjected to 32/22/27 °C (maximum/minimum/mean), 36/26/31 °C, 40/30/35 °C, and 44/34/39 °C for 2, 4 and 6 days in phytotrons at booting stage during 2014 and 2015. Yield and yield components, dry matter partitioning index (DMPI), NSC accumulation and translocation were measured and calculated. The results showed that the increase of high-temperature level and duration significantly reduced grain yield by suppressing spikelet number per panicle, seed-setting rate, and grain weight. Heat stress at booting decreased DMPI in panicles, increased DMPI in stems, but had no significant effect on photosynthetic rate. Stem NSC concentration increased whereas panicles NSC concentration, stem NSC translocation efficiency, and contribution of stem NSC to grain yield decreased. Severe heat stress even transformed the stem into a carbohydrate sink during filling. The heat-tolerant Wuyunjing 24 showed a higher NSC transport capacity under heat stress ...
Source: The Crop Journal - Category: Food Science Source Type: research